Door latch



Aug. 21, 1956 F. J. MccoNNELL DooR LATCH Filed' oct. 21,'1952 I N V ENTOR. /PAW/f /Vc' (ff/NIM BY I I7 7 TOPI/EK United States Patent O DOORLATCH Frank J.- McConnell, New Britain, Conn., assigner to The AmericanHardware Corporation, New Britain, Conn., a corporation of ConnecticutApplication October 21, 1952, Serial No. 315,928 Claims. (Cl. 292-169)This invention relates to a door latch and is embodied 1n a latch unitthat is particularly adapted for use with a cylindrical door lock.

An object of this invention is to provide a latch unit having noveldogging means therein for preventing depression of the latch bolt fromthe exterior of the door, by means of a tool, when the said door isclosed and the latch bolt of said unit is in engagement with the strike.

A further object of this invention is to provide such a unit with alatch bolt dogging mechanism that is simple in construction, inexpensiveto manufacture and is composed of relatively few parts.

Further objects and advantages of this invention will be more clearlyunderstood from the following description and the accompanying drawingsin which:

Fig. 1 is a sectional side view of a cylindrical door lock illustratingthe manner in which the latch unit, shown in elevation, is securedthereto.

Fig. 2 is a front elevational view of the latch unit.

Fig. 3 is a rear elevational view thereof.

Fig. 4 is a plan View of the latch unit, partially in central horizontalsection, illustrating the dogging mechanism in undogging position.

Fig. 5 is a similar view further illustrating the construction of saidmechanism.

Fig. 6 is a side view of the latch unit, partially in central verticalsection.

Fig. 7 is a view similar to Fig. 5, but showing the dogging mechanism indogging position.

Fig. 8 is a sectional end view of the latch unit, taken on line 8-8 ofFig. 6, illustrating the position of the dogging member employed in saidclogging mechanism when in undogging position.

Fig. 9 is a similar View illustrating the clogging member when inclogging position.

Fig. 10 is an exploded isometric view of some of the parts of theclogging mechanism illustrating the respective positions which theyoccupy in the latch unit.

My improved door latch unit includes an elongated casing 5 which iscircular in cross-section and is provided, at its outer end, with anannular flange 6 that is secured between a face plate 7 and a clampingplate 7-a which is fastened to the face plate in a manner well-known tothose skilled in the art and supports the casing relatively thereto;said plates being provided with holes 8 8 therein which receive screwsfor fastening the latch unit to the door.

A latch bolt 9 is slidably mounted within the outer end of the casingand is provided with a flat side 10 having spaced stop shoulders10-1-10-:1 at the inner end thereof which engage the inner surface ofthe face plate 7 adjacent an opening 1li-b therein, similar to the shapeof the bolt, through which a portion of the bolt projects.

Said bolt has a slot 11 extending diametrically across its inner endwhich receives the outer end of a flat retractor har 12 having anopening 13 therein which extends into the slot 11. The bar 12 is rigidlysecured to the bolt 9 by peening the material of the bolt into the ICCopening 13 and over its outer edge as illustrated in Figs. S and 10. Theretractor bar 12 extends through the casing 5 and is provided, at itsinner end, with retractor lugs 12-a12-a.

The casing 5 carries a supporting plate 14 having ears 15-15 extendingperpendicularly from the sides thereof which are received indiametrically opposed slots 16--16 in the wall of the casing and engagethe ends of said slots to locate the supporting plate in properposition. Said supporting plate is also provided with ears 15-a-15-awhich project perpendicularly from the upper and the lower edges of saidplate.

A cup-shaped retainer 17 is telescopically received within the inner endof the casing and abuts the ends of the ears 15*15 and 15-a-15-a on saidsupporting plate which space the end wall 17-a of the retainer from therear surface of said plate. The retainer 17 has a cover plate 18supported against its annular edge and the said supporting plate,retainer and cover plate are held in assembled position by means ofprongs 19 which project fliom the end of the casing 5 and are bent oversaid cover p ate.

The intermediate section of the retractor bar 12 extends through and isslidably supported in an opening 20 in the supporting plate 14- and asimilar opening 21 in the end wall of the cup-shaped retainer 17. Thenarrow inner end portion of the retractor bar projects through anopening 22 in the cover plate 18 that is similar to the openings 20 and21.

The latch unit further includes a camming bar 23 which extends parallelto the retractor bar 12 through the openings 20, 21 and 22 abovementioned. The narrow inner end portion of the camming bar is providedwith a longitudinally extending rib 24 which is slidably received in anotch 25 formed in an ear 26 extending into the opening 22 in the coverplate 18 to provide a guide for the inner end of the camming bar andalso retain it adjacent the retractor bar as illustrated in thedrawings.

The camming bar contains a slot 27 that extends into the outer portionof the bar which is offset relatively to the inner end to provide camsurfaces 28-28 thereon which lead up to elongated platforms 29-29. Thesaid outer end of the camming bar is supported in spaced relation to theretractor bar by a perpendicular extension having shoulders 15d-30 whichengage the side of the retractor bar and a finger Sil-a of reduced widthwhich extends into the opening 13 and is engaged by the outer end of aspring 31 contained in said opening and positioned therein by a finger32 which projects into the opposite end of the spring. The inner end ofthe camming bar has retractor lugs 33-33 thereon similar to the lugs onthe retractor bar, but the camming bar is shorter than the retractor harand said lugs 33-33 are located forwardly of the lugs 12-a-12-a when thelatch is in normal projected position. It will be understood that thespring 31 urges the perpendicular extension on the camming bar intocontact with the end of the latch bolt 9, but permits movement of saidcamming bar relatively to the retractor bar, the nger 3GP-a therebymoving in a direction towards the end of the slot 13 and the linger 32which constitute an abutment means.

The latch bolt 9, the retractor bar 12 and the camming bar 23 areretained in normal extended position, wherein the stop shoulders 1li-aare in engagement with the inner surface of the face plate 7, by meansof a spring 34 which has its outer end contained within an opening 35 inthe bolt and its inner end in engagement with the supporting plate 14and is positioned thereon by a pin 36 which is secured to said plate. l

An auxiliary latch bolt 37 is provided in the latch unit and saidauxiliary bolt has a semi-cylindrical outer end portion 3S that projectsthrough and is slidably supported in a semi-circular notch 39 in theface plate 7 with its llat side adjacent the at side of the latch bolt.The auxiliary bolt has a cylindrical shank 40 projecting therefrom intothe casing which is of a smaller diameter than the end portion 38providing a shoulder 4l thereon. The inner end of said shank is slidablysupported in an opening 42 in the supporting plate 14 and the auxiliarybolt is urged into normal extended position by a spring 43 whichsurrounds the shank and has its outer end in engagement with theshoulder 41 and its inner end abutting the supporting plate 14. Theauxiliary bolt is positioned relatively to the latch bolt 9 by ashoulder 44, provided at the outer end of the shank, which engages therear surface of the bolt 9. The said shank 40 has a notch 45 in one sidethereof having a cam Surface 45 at its inner end.

A dogging plate 47 is contained in the space between the end wall ll7-aof the retainer and the supporting plate 14 and is supported for lateralmovement therein by means of the ears llS-a-lS-a, which projectrearwardly from the upper and the lower edges of said supporting plate,as illustrated in Fig. 6. Said dogging plate has an opening 49 thereinthrough which the retractor bar 12 and camming bar 23 extend. A doggingnger 50 projects into the opening 49 from the side thereof and extendsthrough the slot 27 in the camming bar 23. Spaced abutment surfaces51--51 are provided at the edge of the opening 49 adjacent the dogginglinger 59 and said abutment surfaces lie in alignment with the platforms29-29 on the camming bar. When the latch bolt is in normal extendedposition, the dogging nger is aligned with an opening 52 extendingthrough the intermediate portion of the retractor bar 12.

The dogging plate has a notch 53 in its side edge which receives the endportion of the shank `46 of the auxiliary bolt and the bottom of saidnotch provides an abutment surface 53-a which is urged into engagementwith the periphery of said shank by a U-shaped spring 54 positionedbetween the side of a notch 55 in said plate and the adjacent earproject-ing from the supporting plate.

When the latch bolt and the auxiliary latch bolt are in normal extendedposition, the shank 40 of said auxiliary bolt will be engaged by theabutment surface S3-a on the dogging plate to retain the said plate inthe position illustrated in Fig. 5 wherein the dogging linger 50 isremoved from the opening 52 in the retractor bar 12.

The latch unit above described is particularly adapted for use with acylindrical door latch operating mechanism such as that illustrated inFig. l. Said mechanism generally includes a cylindrical casing 56 havinga retractor 57 slidably mounted therein which includes fingers SS-S thatextend through a notch in the wall of the cylindrical casing 56. Saidretractor is actuated by rotatable rollback means, generally indicatedat 59, which are operated by inner and outer rotatable spindles carriedby the latch operating unit. Said mechanism is usually provided withsuitable dogging means, not shown, which are operable from the inneroperating member to dog the outer operating member against operation,and with key operated means in the outer operating member for retractingthe retractor when the said outer operating member is dogged.

My improved latch unit is secured to the casing 56 of the latchoperating unit by means of rearwardly extending legs 6ft-60 which arebent from the upper and the lower edges of the cover plate 18 and areprovided, at their end portions, with suitable means for engaging theedge of the slot in the casing as illustrated in Fig. l. When inposition thereon, it will be noted that the retractor fingers 58-53 willengage the retractor lugs 3.3-33 on the camming bar while the lugs12-1--12-1 on the retractor bar 12 will be disposed therebehind. It willalso be understood that the camming bar and retractor bar are allowed tomove rearwardly independently of the retractor.

ln describing the operation of the latch unit, let it be assumed thatthe door is open and the mechanisms of the latch unit and the latchoperating unit are in the positions illustrated in Figs. 1 through 5. Asthe door is moved into closed position, the latch bolt will engage thestrike, indicated at 61, and be depressed thereby and the auxiliary bolt37, the retractor bar 12 and the camming bar 23 will move rearwardlyindependently of the retractor. The dogging plate 47 will be retained inundogging position by the platforms 29-29 on the camming bar which willhave moved into the path of the abutment surfaces 51-51 on the doggingplate before the cam surface 46 on the shank 40 of the auxiliary bolthas reached the abutment surface 53-a in said dogging plate andinterference of the dogging finger with the retractor bar will beprevented.

When the door has fully closed, the latch bolt is projected into theopening in the strike by the spring 34, but the auxiliary bolt will beretained in depressed position by engagement with the surface of thestrike, `as illustrated in Fig. 7. As the latch bolt moves outwardlyinto said opening, the spring 31 will cause the camming bar 23 to movetherewith and, as the platforms 29-29 move out of engagement with theabutments 51--51 on the dogging plate, the spring 54 will urge thedogging plate laterally into the notch in the shank of the auxiliarybolt to thereby position the dogging nger in the opening 52 in theretractor bar 12 and prevent rearward movement of the latch bolt.

When the inner or the outer operating member of the latch operating unitis rotated, or the key operated means is actuated, the retractor will beretracted and will first move the camming bar independently of theretractor bar against the spring 31 until the fingers on the retractorengage the lugs 12-a--12-a on the retractor bar, after which furthermovement of the retractor will move the retractor bar and camming bar inunison. However, during independent movement of the camming bar, the camsurfaces 2S-28 thereon are brought into engagement with the abutments51-51 on the dogging plate and, when the rearward movement of theretractor bar is started, said cam surfaces will urge the dogging platelaterally, against the spring 54, to withdraw the dogging finger 50 fromthe opening 52 in the retractor bar before the forward edge of saidopening engages the finger 50 to thereby prevent any interferencebetween the retractor bar and the dogging finger.

When the door is opened and the latch operating unit is returned tonormal position by the spring means contained therein, the springs 34and 43 will urge the latch bolt and the auxiliary latch bolt into normalextended position wherein the shank of said auxiliary bolt will, throughengagement thereof with the abutment surface 53-a in the dogging plate,retain said dogging plate out of dogging position, as illustrated inFigs. 5 and 8.

I claim:

l. In a latch unit, a casing, a latch bolt slidable in said casing andnormally projecting from one end thereof, means for connecting the innerend of said latch bolt to a retractor, an auxiliary bolt slidable insaid casing from a projected to a retracted position, supporting meansfastened to said casing, a dogging member slidable upon said supportingmeans and movable transversely of said latch bolt from a first positionclear of said latch bolt to a dogging position wherein inward movementof the latch bolt by pressure on the outer end thereof is prevented,said auxiliary bolt having cam means thereon engageable with saiddogging member when said auxiliary bolt is in projected position toforce said dogging member out of dogging position, separate cam meansadjacent to and movable with said latch bolt and engaged at its innerend by said retractor, outer stop means on said latch bolt engaged withsaid separate cam means when said latch bolt is in projected positionwhereby said separate cam means will be moved inwardly if pressure isapplied to the outer end of said latch bolt to cam said dogging meansout of dogging position when said auxiliary bolt is in projectedposition, and inner abutment means on said latch bolt spaced from saidouter stop means and permitting limited movement of said separate cammeans inwardly relatively to said latch bolt to cam said dogging meansout of dogging position if said retractor is operated when saidauxiliary bolt is held in retracted position by a strike.

2. In a latch unit, a casing, a latch bolt slidable in said casing andnormally projecting from one end thereof, means for connecting the innerend of said latch bolt to a retractor, an auxiliary bolt slidable insaid casing from a projected to a retracted position, supporting meansfastened to said casing, a dogging member slidable upon said supportingmeans and movable transversely of said latch bolt from a iirst positionclear of said latch bolt to a dogging position wherein inward movementof the latch bolt by pressure on the outer end thereof is prevented,said auxiliary bolt having cam means thereon engageable with saiddogging member when said auxiliary bolt is in projected position toforce said dogging member out of dogging position, separate cam meansadjacent to and movable with said latch bolt and engaged at its innerend by said retractor, said cam means having a cam shoulder and anelongated straight portion engageable with said dogging member, outerstop means on said latch bolt engaged with said separate cam means whensaid latch bolt is in projected position, whereby said separate cammeans will be moved inwardly if pressure is applied to the outer end ofsaid 'latch bolt to cam said dogging means out of dogging position whensaid auxiliary bolt is in projected position, and inner abutment meanson said latch bolt spaced from said outer stop means permitting limitedmovement of said separate cam means inwardly relatively to said latchbolt to cam said dogging means out of dogging position if said retractoris operated when said auxiliary bolt is held in retracted position by astrike.

3. In a latch unit, a casing, a latch bolt slidable in said casing andnormally projecting from one end thereof, means for connecting the innerend of said latch bolt to a retractor, an auxiliary bolt slidable insaid casing from a projected to a retracted position, supporting meansfastened to said casing, a dogging member slidable upon said supportingmeans and movable transversely of said latch bolt from a rst positionclear of said latch bolt to a dogging position wherein inward movementof the latch bolt by pressure on the outer end thereof is prevented,spring means biasing said dogging means into dogging position, saidauxiliary bolt having cam means thereon engageable with said doggingmember when said auxiliary bolt is in projected position to force saiddogging member out of dogging position, separate cam means adjacent toand movable with said latch bolt and engaged at its inner end by saidretractor, outer stop means on said latch bolt engaged with saidseparate cam means when said latch bolt is in projected position wherebysaid separate cam means will be moved inwardly if pressure is applied tothe outer end of said latch bolt to cam said dogging means out ofdogging position when said auxiliary bolt is in projected position,spring means biasing said separate cam means against said stop means,and inner abutment means on said bolt spaced from said outer stop meanspermitting limited movement of said separate cam means inwardlyrelatively to said latch bolt to cam said dogging means out of doggingposition if said retractor is operated when said auxiliary bolt is heldin retracted position by a strike.

4. In a latch unit, a casing, a latch bolt slidable in said casing andnormally projecting from one end thereof, means for connecting the innerend of said latch bolt to a retractor, an auxiliary bolt slidable insaid casing from a projected to a retracted position, supporting meansfastened to said casing, a dogging member slidable upon said supportingmeans and movably transversely of said latch bolt from a iirst positionclear of said latch bolt to a dogging position wherein inward movementof the latch bolt by pressure on the outer end thereof is prevented,spring means biasing said dogging member into dogging position, saidauxiliary bolt having cam means thereon engageable with said doggingmember when said auxiliary bolt is in projected position to force saiddogging member out of dogging position, separate cam means adjacent toand movable with said latch bolt and engaged at its inner end by saidretractor, said separate cam means having a cam shoulder engageable withsaid dogging member, an elongated straight portion extending from saidshoulder, and a hooked outer end extending through an elongated apertureformed in said latch bolt, a compression spring positioned within saidaperture between said bolt and said hooked end for biasing said separatecam means outwardly relative to said latch bolt, said hooked endnormally engaging the bolt, the inner end of said separate cam meanswhen the hooked outer end is against said bolt terminating inwardly ofthe inner end of said latch bolt.

5. In a latch unit, a casing, a latch bolt slidable in said casing andnormally projecting from one end thereof, means for connecting the innerend of said latch bolt to a retractor, an auxiliary bolt slidable insaid casing from a projected to a retracted position, a supporting plateextending across said casing, a retaining member extending across saidcasing adjacent said supporting plate, means spacing said plates apart,a dogging plate slidably mounted between said supporting and retainingplates, spring means urging said dogging plate into dogging position,said supporting plate, retaining plate and dogging plate having normallyaligned openings therethrough receiving said latch bolt and saidauxiliary bolt, said auxiliary bolt having cam means thereon engageablewith said dogging plate when said auxiliary bolt is in projectedposition to force said dogging plate out of dogging position, separatecam means adjacent to and movable with said latch bolt having its innerend extending through said supporting plate, retaining member and saiddogging plate and engaged with said retractor, outer stop means on saidlatch bolt engaged with said separate cam means when said latch bolt isin projected position whereby said separate cam means will be movedinwardly if pressure is applied to the outer end of said latch bolt tocam said dogging means out of dogging position when said auxiliary boltis in projected position, and inner abutment means on said latch boltspaced from said outer stop means and permitting limited movement ofsaid separate cam means inwardly relatively to said latch bolt to camsaid dogging means out of dogging position if said retractor is operatedwhen said auxiliary bolt is held in retracted position by a strike.

References Cited in the tile of this patent UNITED STATES PATENTS1,876,081 Schlage Sept. 6, 1932 2,576,648 Smith Nov. 27, 1951 2,591,647Welch Apr. 1, 1952 2,636,376 McConnell Apr. 28, 1953 2,644,706 McConnellJuly 7, 1953

